It would be so much easier with elimination but ok
1.
x+y=1
minus x
y=1-x
sub
2x-(x-1)=-2
2x-x+1=-2
x+1=-2
x=-3
sub
y=1-x
y=1-(-3)
y=1+3
y=4
(-3,4)
2.
x-2y=2
add 2y
x=2y+2
sub
5(2y+2)-3y=-11
10y+10-3y=-11
7y+10=-11
7y=-21
y=-3
sub
x=2y+2
x=2(-3)+2
x=-6+2
x=-4
(-3,-4)
3.
x-y=3
add y
x=y+3
sub
6(y+3)+4y=13
6y+18+4y=13
10y+18=13
10y=-5
y=-1/2
sub
x=y+3
x=-1/2+3
x=5/2
(5/2,-1/2)
1. (-3,4)
2. (-3,-4)
3.(5/2,-1/2)
Answer:
Problem 1: 
Problem 2: 
Problem 3: 
Step-by-step explanation:
Problem 1:
So we are going to use the following to help us:



So if we make those substitution into the first equation we get:



Factor the
out:

The following is a Pythagorean Identity:
.
We will apply this identity now:

This implies:

We don't need both because both of include points with radius 4.
Problem 2:



Factoring out
from first two terms:

Apply the Pythagorean Identity I mentioned above from problem 1:


or if we factor out r:


r=0 is actually included in the other equation since when theta=0, r=0.
Problem 3:


The equation has the form Y= a + bX,
Where:
Y is the dependent variable (that's the variable that goes on the Y axis).
X is the independent variable (i.e. it is plotted on the X axis).
b is the slope of the line.
a is the y-intercept.
Answer:
Believe on what you heart says